Two world maps on the same mount, probably orginally a double page from a book, laid down inside a brown leather cover and heavily hand coloured (the colouring is so heavy it was long thought to be a manuscript, in fact a method employed by contemporaries to make prints look less like prints). This is the earliest extant map to show the world in 360 degrees of longitude and 180 degrees of latitude within an oval projection, a form which would be adopted by many major cartographers later in the century. Columbus' place names for central America are placed (as claimed by Columbus) along the coast of Asia, which extends to the eastward following the Ptolemaic conception of the continent, into a peninsular North America.

The main issue for cartographers in the early sixteenth century was how to reconcile the Ptolemaic understanding of world geography with the geographical knowledge which reached Europe following the turn of the century voyages of exploration. This map is Rosselli's attempt at that feat, incorporating the latest information into a Renaissance geographical tradition. It is particularly important as ab extant world map by a contemporary cartographer which depicts Columbus's own understanding of the geographical results of his fourth voyage.